1. Field of the Invention
The invention relates to a valve of the type having a housing, a solenoid arranged in the housing, a pin movable by the solenoid, a piston connected to the pin, and a seal that seals the piston against the housing.
2. Related Art
Valves of this type are used, inter alia, as a diverting air valve on a turbocharger in motor vehicles, so as to open a bypass to the suction side in an overrun mode, as a result of which excessively abrupt braking of the turbocharger is prevented and rapid starting up is ensured. The opening and closing of the bypass takes place via the piston that acts as a closing member and opens or closes an opening in the bypass line. For closing purposes, the piston is moved into the closed position by a spring. For opening purposes, the piston is moved out of the closed position counter to the spring force by the solenoid. In order to seal the housing with respect to the bypass line, a seal that bears against the outer face of the piston is arranged in the housing. During opening and closing of the piston, the piston moves with respect to the seal. So that the piston is not pressed out of the housing by the spring during transport and before the installation on the bypass line, a flange is integrally formed at that end of the piston that faces the solenoid. The flange presses against the seal and thus prevents the release of the piston from the housing. It is disadvantageous that the seal can be damaged by the piston as a consequence of the transport movements. The possibility of such damage makes it necessary to perform additional tests in order to avoid failures of the valve during operation.